Photographic-type composing apparatus

ABSTRACT

Photographic-type composing apparatus in which transparent characters are carried on a continuously revolving disc. A shutter and a flashlamp are mounted translate with the disc. As each selected character moves past a projection window in the shutter, it is illuminated with a short, intense flash of light from the flashlamp. The character image is projected through an optical system onto photographic film. After the projection of each character, the disc, the shutter and the flashlamp are moved as a unit in a direction parallel to the line of characters being composed by a distance equal to the relative width of the character next to be projected. During this movement, the optical system and the film remain stationary. The point size of images on the film is changed simply by adjusting the magnification of the optical system; the character spacing will remain correct without changing the amount of movement of the disc.

United States Patent l l 1 UN Inventor Louis M. Moyroud 202 Grove Way.Delray Beach. Fla. 33444 690,720

Dec. 13, i967 July 6, 1971 June 10, 1966 Great Britain Appl. No FiledPatented Priority PHOTOGRAPHlC-TYPE COMPOSING APPARATUS 26 Claims, 17Drawing Figs.

U.S. Cl 95/4.5 lnt.Cl B4lb 17/10 Field of Search 95/4.5

References Cited UNITED STATES PATENTS 2/l965 Wilson 9/1965 Blakely....3/1967 Proud 3,347.l4() l0/l967 Ritchie 3.434.402 3/1969 McCall Primarylz'xammer -lohn M. Horan Altorney-Richard F Bannasch ABSTRACT:Photographictype composing apparatus in which transparent characters arecarried on a continuously revolving disc A shutter and a flashlamp aremounted translate with the disc As each selected character moves past aprojection window in the shutter, it is illuminated with a short,intense flash of light from the flashlamp. The character image isprojected through an optical system onto photographic film.

PATENTEUJUL slsm 3,590,705

SHEET 1 [)F 7 INVENTOR 100/: M M Via 1/0 ATTORNEY PATENTEU JUL 6 |97|SHEET 7 BF 7 ATTORN EYS- PHOTOGRAPHlC-TYPE COMPOSING APPARATUS One ofthe most important advantages of photographic-type composing orphotocomposing machines over systems using hot metal resides in thecapability of photocomposing machines to produce characters of differentpoint sizes from the same matrix character. The different sizes aregenerally obtained either by projecting images onto a photosensitivesurface by lenses of various predetermined focal lengths, or byrefocusing a single lens for different magnification ratios, such as bythe use ofa zoom lens. In some prior systems, for example, in machinescommercially known under the trademark PHOTON Model 200 series, a lensturret provided with lenses of different focal lengths is utilized toproject character images of predetermined point sizes. In this class ofmachine it is, of course, necessary to provide means to variably spacecharacter images on the film taking into account not only the relativecharacter widths of a given alphabet (based, for example, on a fixednumber of units to an Em), but also it is necessary to introduce afactor representing the point size of the character on the film. Thespace allocated on the film for each character can thus be determined bymultiplying the basic relative character width (in units) by a setfactor representing the ultimate point size, as explained in U.S. Pat.No. 2,876,687. Characters can be spaced on the film by moving the filmeither after or before each character projection. In any case, in suchprior systems the displacement of character images relative to the filmalways represent a discrete number of widthunits dependent on pointsize, as is described in U.S.

Pat. No. 2,876,687. In order to handle a relatively large number ofelementary width units, multiples of which are used to measure thewidths of characters of different sizes, it has been necessary to userather complex mechanisms such as that described in U.S. Pat. No.2,806,574 or in U.S. Pat. No. 2,678,713.

An object of this invention is to provide an improved photographic-typecomposing machine in which character spacing is accomplished withoutmoving the film or optical system. Another object of this invention isto provide an improved photographic-type composing machine capable ofproducing character images of different sizes with simple andinexpensive means for correctly spacing these characters according totheir relative widths and their sizes.

A feature of the invention is the provision of a photographic-typecomposing machine having a movable character matrix which can bedisplaced by discrete steps representing relative character widths inorder to properly space these characters on a film regardless of theoptical enlargement or reduction ratio used in the machine.

Another feature of the invention is the provision in a photographic-typecomposing machine of style selecting means controlled by the characterspacing mechanism.

Another feature of the invention is the provision in a photographic-typecomposing machine of a character bearing matrix movable in discreteincrements during the composition of a line while the optical system andfilm are stationary.

The foregoing and other objects, features and advantages of the presentinvention will be apparent from the following more particulardescription of a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a perspective, partially exploded view of a preferredembodiment of the photocomposing machine of the present invention;

FIG. 2 is a cross-sectional and partially schematic view taken alongline 2-2 of FIG. 1;

FIG. 3 is a plan view of the machine components shown in FIG. 2; 1

FIG. 4 is an end elevation view of the machine components shown in FIG.2;

FIG. 5 is an enlarged, partially schematic view of a portion of themachine shown in FIGS. 1 through 4;

FIG. 6 is a simplified perspective drawing illustrating schematicallysome of the operating principles of the present invention;

FIG. 7 is a schematic diagram further illustrating operating principlesof the invention;

FIG. 8 shows analternative form of the character disc of the presentinvention;

FIG. 9 is a partially cross-sectional view of an alternative form of thecharacter composing apparatus of the present invention;

FIG. 10 is an end elevation view of the apparatus shown in FIG. 9;

FIG. 11 is a plan view of a portion of the apparatus shown in FIGS. 9and 10;

FIG. 12 is an elevation view of a portion of the apparatus shown in FIG.11;

FIG. 13 is a view illustrating characters recorded on film in order toillustrate one of the problems solved by the present invention;

FIG. 14 is a partially cross-sectional view taken along line l4l4 ofFlG.2;

FIG. 15 is a cross-sectional view taken along line 15-15 of FIG. 5;

FIG. 16 is a cross-sectional view taken along line 16-16 of FIG. 5; and

FIG. 17 is a schematic circuit diagram of the preferred control circuitfor the photocomposing machine of the present invention.

QVERALLIOPERATION A preferred embodiment of the photocomposing machineof the present invention is shown in FIG. I. The photocomposing machine30 is designed to operate upon instructions given to it by means of apunched tape 32. The tape can be prepared by typing the matter to becomposed on the keyboard of an inexpensive counting tape perforator (notshown) such as those which are sold under the trademarks 'I'TS" orJUSTOWRITER." The punched tape 32 contains coded patterns identifyingeach character to be composed, other patterns signalling the end of aline of characters, and other information necessary to thephotocomposition process. After having appropriately adjusted thecontrols 36 of the machine, the operator places the punched tape 32 in atape reader 34. Then, the machine automatically reads in instructions onthe tape and an electrical control unit 40 and a photographic unit 42prepare a strip of film with a completely justified composition recordedon the film. The operator removes the film from a film magazine 38located at the top of the machine 30, and then has the film developed.The developed film is utilized in the production of printing plates thatare used for printing newspapers, magazines and books in the usualmanner.

Means are provided for automatically shifting the sytle" of thecharacters being recorded on the film in response to appropriate signalsfrom the tape 32. As is shown in FIGS. 1 through 4, and particularly inFIG. 5, an opaque disc 48 has a plurality of concentric rings 41, 43 and45 of transparent characters 47, 49 and 51. The characters in each ringpreferably are all of one typeface; e.g., all of Bodini Roman, or

all of Bodini Italic, etc. The photocomposing machine automaticallyselects among the typeface rings on the disc 48 in response toappropriate signals from the tape 32. Ifa typeface not on the disc 48 isdesired, the disc can be easily and quickly replaced by another discbearing characters of the typeface desired.

In accordance with another advantageous feature of the invention, thesizes or the images recorded on the film can be adjusted simply bymoving levers 44 and 46 'on the side of the photographic unit 42. Thismovement adjusts the optical system to provide greater or lessermagnification of the characters.

' OVERALL OPERATION or THEVPIHOTOGRAPI-IIC UNIT Referring now to FIGS. 2and 5, as well as to FIG. I, the principal components of the opticalunit 42 of the photocomposing machine 30 are mounted in a housing 50.The optical components include the character disc 48, a flashlamp 52, aprojection lens 54, and first, second and third front-surfaced mirrors56, 58 and 60. A strip of film 62 is shown schematically in FIG. 2supported by rollers 64, 66, 68, and 70 in a horizontal position in themagazine 38.

The disc 48 rotates continuously so as to move the characters in one ofthe concentric rings 41, 43 or 45 past a projection position defined byan aperture 61 in a shutter 63 (see FIG. 5). The flash tube 52 flasheslight through the aperture 61 at the instant when the character to beprojected is properly located at the aperture to project light throughthe transparent character on the disc. The light rays are reflectedalong an optical path indicated by the line 72 in FIG. 2. Light passesthrough the projection lens 54, is reflected off the mirrors 56, 58 and60, and then passes upwardly to the film 62 where the projectedcharacter is imaged. The operation of the flashlamp 52 is substantiallythe same as is described in U.S. Pat. No. 2,775,l72.

In accordance with one advantageous feature of the presentinvention,'the character disc 48 is rotatably mounted on a slidablecarriage 74 (see FIG. 4). Also mounted on the carriage 74 is the flashassembly which includes the flashlamp 52 and the shutter 63. While thecharacter disc 48 rotates, the carriage 74 moves horizontally after eachflash in a step whose length is equal to the relative width ofthecharacters next to be projected. If an interword space is required next,the carriage moves the length of the interword space as computed by thejustifying apparatus of the electrical control unit 40.

Although the carriage is described as moving the width of the nextcharacter to be projected in the preferred embodiment it should be notedthat man alternative embodiment it could be moved the width of thecharacter previously projected following each flash.

Automatic film advancing means of a type known in the art is provided sothat when a full line of characters has been composed on the film 62,the film will be advanced (moved to the left in FIG.- 2) to a newposition at which the film is to be exposed for the composition of thenext line.

Changes in the point size of characters on the film 62 are obtained inthe preferred embodiment of the invention shown in FIGS. 1 through5'-.by, in effect, moving the lens 54 either I closer to or farther awayfrom the film 62 in order to change the magnification provided by thelens 54; that is, the lens 54 is moved either tothe left or the right asit is shown in FIG. 2 in order to change itsmagnification and thus tochange the ultimate point size of the characters on the film. Every timethe lens 54 is moved to the left or right, its focal point shifts.Therefore, for each such movement of the lens 54 the mirrors 56 and 58also must be moved by a certain amount to brin the images produced bythe lens 54 back into focus on the film 62. Because of the use of themirrors, neither the film 62 nor the carriage 74 need to be moved torefocus the images on the film. This simplifies the optical unitconsiderably.

Before proceeding further with the detailed description of the opticalsystem, the principles of its operation will be described.

OPERATION PRINCIPLES OF THE OPTICAL SYSTEM Referring now to theschematic representation in FIG. 6, the character or matrix disc 48 andflashlamp 52 can slide along a path Y-Y' parallel to the line X-X'representing the base line of a'composed line of characters on the film62. Selected characters of the matrix 48 are projected through astationary lens or lens system 80 onto the film 62 which also isstationary during composition of a line. It has been assumed in drawingFIG. 6 that the disc 48 shown in solid lines is located along line Y-Y'at a position appropriate for projecting the first character of the lineof text of length L. The first character to be projected is shown at 82on the disc. Its image will be located at point 84 on the film, at thebeginning'of the line. After the disc carriage has moved a distance d,the disc as moved to projection position indicated in dashed lines andthe location of projected characters has also moved, as shown, to aposition indicated at 86. It can be seen quite readily that the distanceL which the image position moves on the film 62 when the disc 48 moves adistance d depends upon the enlargement or reduction ratio of the lenssystem 80. Thus, the spacing between characters and words in a linedepends upon the enlargement or reduction ratio of the lens system 80.Therefore, the movement of the disc 48 betweenprojections of characterscan be limited to the relative widths of the characters on the matrixdisc and the ultimate point size of the image can be adjusted simply byadjusting the magnification or reduction ratio of the lens system,without the need for varying the movement of the disc. The foregoing isa major principle used in the present invention, and is termed opticalleverage." Since the amount of disc movement used to provide characterspacing need not change when the point size is changed, the arrangementdescribed above provides simple and inexpensive means for projecting andproperly spacing character images. I

The schematic representation of FIG. 7 further illustrates the opticalleverage system of the invention. A lens 88 of correct focal length forfocusing images on the film is positioned halfway between the plane ofthe matrix characters and the plane of the film so that it will projectonto the film character images having the same size as the characters onthe disc 48. If lens 88 now is replaced by another lens 90, also ofcorrect focal length and located on the same optical axis as lens 88 buthaving an enlargement ratio of magnification of three, characterimagesprojected on the film will be 3 times as large as the characters on thedisc. A character projected from a character projection position 92 byeither lens 88 or is imaged in the film plane at a point 94 on theoptical axis 96. After the disc has moved a distance s however, the samecharacter projection position 92 has moved to a point 98 and newcharacters will be projected to a point 100 on the film by lens 88, orto a point 102 by the lens 90. The distance s between points 94 and 102is 3 times s."

As a specific example, assume thatthe so-called units of an Em system"is utilized, and that a character on the disc 48 to be projected is nineunits of an Em wide. Assume also that the character is of six point"size. If six point size characters are desired on the film 62, the lens88 with an enlargement ratio of one is used, and the image of thenine-unit character also is nine units of an Em wide. If, however, it isdesired that the character images be much larger, say of 18 point size,then the lens 90 having an enlargement ratio of three is used instead ofthe lens 88, and the image produced will be 3 times wider that is therelative units in 18-point are 3 times as wide as they are in six-point.

As is well known in the art, different lenses each having a differentmagnification corresponding to a specific point-size value and adifferent focal length can be mounted in a lens turret and theappropriate lens can be brought into position for use by rotation of theturret. However, it is not necessary to use separate lenses giving exactpoint-size values, and it may be desired to provide continuous variationof the enlargement or reduction ratio. Thus, by using a single zoom"lens rather than separate lenses of various focal lengths, it ispossible to adjust the enlargement to any point size within the limitsof the lens. The same result can be achieved by the use of a single lenswith proper size and focus and by displacing the relative positions ofthe matrix, the lens and the film; that is, by moving those elementstowards or away from one another in order to change the magnificationproduced by the lens and to keep.

the images in focus on the film. It is the latter arrangement which isused in the preferred embodiment of the invention which has beendescribed above in connection with FIGS. 1 through 5.

The operational principles of the optical system having been explained,the details of its operation now will be described.

MOVEMENT OF THE. CHARACTER DISC AND FLASH ASSEMBLY Referringparticularly to FIGS. 2, 3 and 4, the character disc 48 is rotatablymounted on the carriage 74 by means of a shaft 104 (FIG. 2). A toothedpulley 108 is secured to the right end of shaft 104. A drive motor 110(FIG. 3) rotates a toothed pulley 112 which drives a correspondinglytoothed flexible belt 114. The belt 114 passes over a pair of pulleys116 (FIGS. 3 and 4), engages the upper surface of the toothed pulley 108(FIG. 2), and passes around an idler pulley 118 (FIG. 4). A roller 120(FIG. 2) which is rotatably mounted on the carriage 74 pressesdownwardly against the belt 1 14 directly above the center of the pulley108 so as to insure positive driving engagement between the belt 114 andthe pulley 108. The motor 110 thus rotates the disc 48 continuously, ata constant rate of speed. The preferred speed is approximatelyrevolutions per second in the preferred embodiment being described.

The disc 48 is detachably mounted on the left end of shaft 104 by meansof an easily detachable screw knob 107 (FIG. 3). The disc 48 is made ofa transparent material such as a hard plastic or glass coated on oneside with opaque material. The opaque material is absent in the areasdefining the characters, thus forming transparent characters on thedisc. The transparent characters can be formed by photographictechniques well known in the art, for example as described in US. Pat.No. 2,715,862.

The carriage 74, which preferably is made of a light metal such asaluminum, is mounted for horizontal movement on two slide bars 122 and124 whose ends are secured to support members 126 and 128. The carriage74 has a pair of depending arms 130 and 132 each of which is slidablymounted on the lower slide bar 124 by means of roller bearings. As isshown in FIG. 2, the carriage 74 has two vertically mounted rollers 126and 138 which are positioned on opposite sides of the upper slide bar122 to act as low-friction guide members for guiding the carriage in itshorizontal movements along the guide bar 122.

The carriage 74 is moved horizontally in discrete increments by aconventional stepping motor 140 (see FIG. 2) which drives a spur gear orpinion 142 which, in turn, drives a rack 144 which is secured to thecarriage 74. During composition of a line, the carriage 74 moves to theleft as shown in FIG. 4, and returns to the farthest right position tostart a new line. It is desired that the stepping speed of the steppingmotor 140 be high, especially since the motor is used for driving thecarriage both in the forward and return directions. A stepping motorwith a stepping rate of approximately 1200 steps per second has beenfound to be satisfactory for use in the preferred embodiment of theinvention.

The flashlamp 52, which preferably is of relatively light weight andproduces a very short but intense flash of light, is mounted, togetherwith the shutter 63, on a mounting member 146 which is swingably mountedon the carriage 74 by means of a pin 148 (see FIGS. 4 and 5). Referringspecifically to FIG. 4, the mounting member 146 can be swung clockwiseto a position where the left edge of the support and the flash unit arebeyond the right edge of the disc 48, thus facilitating the changing ofcharacter discs. The character discs are changed easily simply byswinging the support 146 to the right, removing the knob 107, removingthe disc 48 and replacing it with another and swinging the support 146back into position. A spring and a stop member (not shown) may beprovided; the spring to return the support 146 counterclockwise to itsposition in front of the disc 48, and the stop member to stop the returnmovement ofthe support 146 at the proper position.

The above-described arrangement in which the character disc 48, theflashlamp 52 and the shutter 63 all move together as a single unit inorder to provide character spacing in the composition of a line ofcharacters is highly advantageous. First, by carrying the flashlampalong with the character disc, the use of complicated optical couplingmeans between the two is avoided. Carrying the shutter 63 along with thecharacter disc 48 also provides a substantial advantage in that styleselection among the various rows of characters on the disc can beaccomplished simply and with a minimum of mechanical or electricalapparatus. All of these factors combine to produce an extremely simple,reliable, and relatively inexpensive character spacing mechanism.

Also carried on the carriage (see FIG. 5) is a slit indicatingphotodiode 220 which generates an electrical signal each time one of thetransparent slits 216 or 218 allows a light beam to impinge on theactive area of the photodiode as is well known in the art. Eachtransparent slit 216 is associated with a radial matrix characterposition and the electrical pulse generated by the passage of a slitbetween the photodiode and the light source is transmitted to theelectronic control unit as more fully described hereinafter.

AUTOMATIC STYLE SELECTION MECHANISM The mechanism for selecting whichrow characters are to be projected from is shown in FIGS. 4 and 5.Referring particularly to FIG. 5, the shutter 63 is pivotally mounted atpoint 158 on a plate 159 which is secured to the support 146 (see FIG.16). The shutter 63 is a relatively thin strip of metal with an enlargedupper end with a square hole in it. The hole 61 is large enough toencompass any character on the disc and allow projection of thecharacter. The enlarged end of the shutter 63 is large enough tocompletely cover the light outlet opening of the flashlamp 52 so thatlight flashes will pass only through the aperture 61.

The shutter 63 is pivotable about the point 158 to three differentpositions as indicated at 61, 161 and 162 so as to align the aperture 6]with one of the three concentric rings 41, 43, 45 of characters on thedisc. It should be understood, of course, that more than three rings ofcharacters can be provided on a disc if desired, and the shutter can beappropriately designed to be shifted to any one of the rows ofcharacters.

The particular mechanism illustrated in FIG. 5 for moving the shutter toone of the three positions comprises a pair of solenoids 150 and 152whose plungers abut against the flexible portion of a spring blade 154which is secured to the plate 159 at point 156. The left end of theblade 154 is secured at 160 to the lower portion of the arm of shutter63 at a position above the pivot point 158. When neither solenoid isenergized, the blade 154 takes the position shown in'FIG. 5 and theaperture 61 s aligned in the position shown in solid lines in FIG. 5with the center character ring 43. When solenoid 152 is energized butsolenoid 150 is not, the plunger of solenoid 152 thrusts the blade 1S4upwardly and forces the shutter 63 to pivot to the left to a position161 in alignment with the innermost ring of characters 41. If solenoid150 is energized and solenoid 152 is not, the plunger of solenoid 150thrusts the blade 1S4 downwardly and forces the shutter 63 to pivot tothe right to position 162 in which the aperture 61 is aligned with theoutermost character ring 45. Style change instructions are typed by theoperator and signals are punched into the tape 32 which when decoded bythe electronic control circuit cause operation of the solenoids to shiftstyles.

The above style selection arrangement is simple and lightweight. Theenergization of the solenoids is rapid enough so that typeface changescan be made rapidly without stopping the composition of a line. Forexample, one word in a line of Roman type may be italicized by shiftingto the italics ring and back again without a pause in the composition ofthe line.

Another advantageous feature of the style selection mechanism justdescribed is that the disc 48 and shutter 63 are located relative to oneanother so that the characters move vertically past the shutter, and thecharacter style rings are separated from one another horizontally at theshutter location. Thus, movement of the shutter 63 for style changes isin a horizontal direction, the same direction as the direction in whichthe carriage 74 moves to space characters. Because both the carriage andthe shutter move horizontally, unwanted character image displacement canbe compensated for quite simply be merely instructing the stepping motor140 to move the carriage 74 either forwardly or backwardly by a numberof steps appropriate to compensate for the movement of the shutter. Forinstance in a preferred embodiment of the invention the character ringsare radially spaced from each other by 32 relative units. Accordingly,to change from the character ring 43 to 41 the shutter is moved so theaperture 61 is in position 161 and the carriage is moved backward 32steps. Thus, absolutely no additional mechanism is needed to make thiscorrection, and the simplicity and reliability of the photocompositionmachine is enhanced.

' POINT-SIZE CHANGING MECHANISM As has been indicated above, in order tochange the point size of the characterimages on the film 62, highly adbyusing one of a number of well-known autofocusing ment of the mirrors 56and 58 each time the lens 54 is moved in order to refocus the image onthe film. In order for the image to be focused on the film 62, theelements of the optical system always must be positioned so as tosatisfy the following equation: 7 .Z. P'. .f

In which: i V

P is the length of the optical path from the characters on disc 48 tothe lens 54;

P is the length of the optical path from the lens 54 tothe film 62; and

f is the focal length of the lens54. v I v It can be seen from the aboveequation that the distance the mirrors 56 and 58 must movein ordertosatisfy the equation is not the same as the distance moved by the lens54. Thus, in accordance with another aspect of the present invention,the lens 54 and the mirrors 56 and 58 are mounted for independentmovement towards and away from the plane of the character disc 48. I v rSpecifically, the lens 54 is mounted on a support member 164 (FIG. 2which is secured to a slide member, 165 which is slidably mounted on atrack 166. Similarly, the mirrors 56 and 58'are mounted on anothersupport member168-which is secured to another slide member, 165 whichalso slides on the track 166. i v v Referringparticularly to FIG. 3, theadjustment levers 44 and 46 (also see FIG. 1) whichextend outside of thehousing of the photographic unit'42, aresecured, respectively, to theslide members for the lens support 164 and the mirror support 168. Eachlever has a main link 170 which is secured to the slide member 165 (seeFIG. 14) and has a somewhat pointed outermost end 172. A pivot member174 with a similarly pointed outermost end is pivotally connected at 176to the link 170. The pivot member 174 also is pivotally connected at apoint 178 which is spaced from the point 176 to an actuating link 1 80which is connected at its innermost end 182 to a pawl 184. Each of thepawls v184 has a pointed tip which normally is biased by a spring intoone of a plurality of notches 186 in a bar 190 extending longitudinallyin a direction parallel to the track 166. The bar 190 is mounted in thephotographic unit by means of support brackets 192. The engagement ofthe pawls in the notches positions the lens 54 and the mirrors 56 and 58in place. An operator can squeeze the pointed ends of the members 172and 174 together so as to pull the actuating lever 180 and pull thepawls 1 84 our of the notches and release the lens 54 and mirrors 56 and58 for movement. As is shown in FIG. 14, a pointer 194 is secured nearthe outermost edge of each lever 172, and each adjustment lever 44 and46 extends through an elongated slot 195 in the housing of theopticalunit. A point-size scale member 193 is mounted at the edge of each slotso that the pointers indicate the point size of the characters beingprojected on the film. The notches in the bar 190 are spaced relative toone another so that when the pawls 184 are engaged in selected .onesofthe notches, the optical assembly will produce precisely focused imagesof a desired point size on the film. The point size produced isindicated on the scales 193 which are within clear view of the operator.r

It should be noted that in determining the spacings of the notches 186for the mirrors 56 and 58, the movement of both mirrors simultaneouslycauses a change in the length of the optical path between the lens andthe film which is twice the actual amount of movement of the mirrorsbecause of the fact that two separate segments of the path are beinglengthened or shortened by movement of the two mirrors simultaneously.

It should be readily apparent to one skilled in the art that many othermechanisms can be provided for adjusting the relative positions of thelens 54 and the mirrors 56 and 58. The adjustment could be made byadjusting only one lever orknob mechanisms which automatically maintainthe system in focus while its magnification is being changed. AIso,appropriate motors and drive arrangements could be used to move theoptical components automatically in response to electrical pointsizechange signals developed in the perforated tape. However, in keepingwith one of the objects of the invention, the point-size adjustmentmeans preferably is kept in the form shown in the drawings in order tokeep it simple and inexpensive.

The lens 54 should be a precision lens preferably known in the art as aprocess lens," and should have a wide enough angle of view to see"characters presented atany position along the extent of travel of thecarriage 74. A lens angle of 24 has been found to be sufficient inpractice. The mirrors 56, 58 and 60 preferably are front-surfaced.

The above described point-size adjustment system is highly advantageousin that it is considerably less expensive and decisively more compactthan would be a lens turret providing the same number of point-sizeadjustments. Furthermore, although it may be preferred to providedefinite positions at which the levers 44 and 46 may be located toprovide only several specific point sizes bysimply making the notches126 very close together and regularly spaced, or by providing othermeans to releasably hold the lens 54 and mirrors 56 and 58 in place, itis possible to provide continuous point-size adjustment over a rangewithin the scope of the lens 54. Continuous adjustment is not possiblewith a lens turret.

CORRECTION OF POINT-SIZE CIIANGE DISPLACEMENTS FIG. 13 illustrates therelative positions on the film 62 of a character 200 of one point sizeand the same character 202 after its point size has been increased bythe point-size change mechanism described above. It can be seen that theright edge of the character is displaced to the right from the rightedge 206 of the character 200 by a distance w. Means is provided inaccordance with the present invention for correcting such displacement.Briefly described, the correction means'causes the stepping motor 140 tostep in a forward direction in an amount proportional to the point-sizechange in order to bring the right edge of the new character 202 intoalignment with the right edge 206 of the original character 200. If thepointsize change is a reduction instead of an enlargement, the carriageis moved backwardly to make the correction.

Part of the specific means used for producing the above corrections isillustrated in FIG. 14 as well as in FIG. 3. Secured to the member is ablock 208 of insulating material with five electrically conductivespring blade contactv arms 210 bearing against a code panel 212 mountedon a support bracket 214. The code panel 212 has a coded array ofconductive and insulating segments aligned in the paths along which thebrushes 210 move when the lens support 154 is moved along the track 166.In each position of the lens 54 in which the pawl 184 can rest in anotch 186 on the bar 190, there is a separate pattern of conductive andinsulating segments which are contacted by the brushes 210. Electricalcircuitry (not shown) is provided to apply either a voltage or novoltage to each of the brushes 210, so that the pattern of the voltageson the brushes is in binary coded form, with each position of thesupport 165 being represented by a different binary number. The signalsfrom the brushes 210 then are converted by the electronic controlcircuit which will be described in detail below which causes thestepping motor 140 to step forwardly and backwardly by a number stepsproportional to the change in magnification. Turning back to FIG. 13 itcan be seen that the larger M 202 is displaced downwardly from theoriginal base line 204 of the smaller m 200 by a distance H. This can becorrected in two ways. In a preferred embodiment the character to beprojected from the matrix disc is only flashed when its base coincideswith the optical axis 72 of lens 54. In this case only the upper half ofthe lens 54 is used and no matter what point size is used all charactersare imaged on the film on the same base line rather than as shown inFIG. 13.

However, in some cases it may prove desirable to use more than half oflens 54; for example to avoid vignetting when projecting at larger pointsizes. In such cases the characters as projected onto the film will beon different base lines in different magnifications as shown in FIG. 13.In which case the correction can be made by displacing the filmforwardly 'or backwardly by a distance H in much the same manner as wasdescribed in relation to the carriage above.

OPERATION OF ELECTRONIC CONTROL CIRCUIT The control circuit shownschematically in FIG. 17 has three main cycles of operation and operatesin much the same way as that described in US. Pat. No. 3,273,475:

A. the rea cycle during which the tape reader 34 reads the informationfrom the tape 32 into the control circuit;

B. The justification cycle during which the control circuit computes theproper spacing between words for producing a fully justified line ofcharacters; and

C. The exposure cycle during which the characters are projected upon thefilm.

Each of these three main operating cycles is repeated for thecomposition of each line of characters. The read and justifying cyclesoccur during the time in which thecarriage 74 is returning from itspoint of furthest advance to its starting position. After the carriagehas traversed the film in the composition of a line of characters, thefilm is shifted to a new position and the carriage is returned to thestarting position so that a new line of characters can be composed onthe film.

The control circuit shown in FIG. 17 includes the tape reader 34,storage means 224 which preferably is a multicore magnetic memory, aninformation register 226 and an address register 228. Also included isan input device 230 for providing a binary input signal representing thedesired length of a composed line of characters. Prior to composition,the line length input device is operated to supply a line length signalto an accumulator 232. The value of the line length signal may be seteither manually or automatically by means of signals stored on thepunched tape 32.

As has been described above, a number of different discs 48 can be usedin the machine 30, each disc bearing characters of a different typeface.For each different disc 48 there is a special program tape which is runthrough the tape reader 34 prior to the composition of characters. Bythis means the relative widths of the characters on that particular discare stored in the memory 224 together with special internal codes forthe handling of special functions and instructions for following thesequence of computing and storage steps to be described next. When thisprogramming has been accomplished, the control circuit is prepared forreception of the paper tape.

A. The Read Cycle During the read cycle, the punched tape 32 bearing thecharacter-representative signals and special function code is fed intothe tape reader 34, and each character is processed according to thefollowing eight steps, the sequence of which is directed by the programalready stored in the computer:

I. First, the coded signal representing the character is read into theinformation register 226 and the line storage portion of memory 224 bythe tape reader 34.

2. Next, the line storage address in the address register 228 istransfcred into a temporary storage device 234, and the codeconfiguration is now transferred from the information register 226 to aposition register 236.

3. Next, the address register 228 is cleared or reset" by means ofasignal from a source 238.

4. After the address register 228 has been cleared, the codeconfiguration is transferred from the position register 236 to theaddress register. The code configuration plus a combination of the threehigh order bits of the address correspond to the address in memory 224where the width for that particular character is stored.

5. Next, the width information which is stored in that particularaddress is read out of the memory into the information register 226 andis regenerated and stored at that address in the memory once again.

6. The width information form the memory is sent to the width register240 by way of the information register 220. Simultaneously, a clearingsignal is sent to the address register 228.

7. The character width information is shifted from the width register240 to an adder-subtractor 242 which subtracts the value of thecharacter width from the value stored in the accumulator 232.

B. The information or line storage address stored in temporary addressunit 234 is returned to the address register 228 in preparation for thereading of the next character.

As each new character appears at the tape reader 34, the control systemrepeats the above eight cycles until finally an end-of-line signal isread. Then the tape reader 34 stops until the justification and exposurecycles have been completed and it is time to read another line ofcharacters.

During the reading of a line of characters in the manner describedabove, function signals stored on the tape, such as those identifyinginterword spaces, style changes or end-ofline signals, etc, aretransmitted to a function decoder 244 which decodes the signals andtransmits them to a quotient register, andthe spaces counter 246 countsinterword spaces for use in the justification calculation. The typefaceunit 248 is a register which instructs the address register 228 toaddress a certain portion of memory 224, the portion of the memorycorresponding to the style and Case'f (i.e., uppercase or lowercase) ofthe characters being read into the memory.

B. Justification Cycle As soon as the end-of-line signal is read fromthe tape, the justification cycle starts. It should be recalled thatboth the read and justification cycles take place while the carriage 74is returning to its starting position. The quotient and spaces counter246, and adder-subtractor 242, the accumulator 232, and a remaindercounter 250 all compromise the justification circuit. The number ofinterwords is divided into the deficit in the accumulation 232 by meansof repeated subtraction, thereby yielding a quotient which is stored inthe quotient register 246 and represents the interword expansionnecessary to justify the line. The remainder of an imperfect division isstored in the remainder counter 250. The amount in the remainder counterrepresents the number of interword spaces which will receive one extraunit of escapement.

C. Exposure Cycle A limit switch (not shown in FIG. 17) is closed by thecarriage 74 when it returns to its initial position, and this signalsthe start of the exposure cycle. The exposure cycle consists of twosteps, an exposure step during which the character is projected, and anescapement" step during which the carriage 74 is moved by stepping motorto the proper position for projection of the next character.

In the exposure step, the character code signals are read out of thememory 224 and into the information register 226. The

typeface codes via the function decoder condition the typeface unit 248according to the particular typeface of the character being projected;The typeface unit 248 sends a style signal to a shutter control unit 252which in turn sends an electrical impulse to one or the other of thesolenoids 150 or 152, or to neither, in order to position the shutter 63over one of the three rows 41, 43 or 45 or characters on the disc 48.The typeface unit also registerswhether the character to be projected isuppercase or lowercase;

The position register 236 receives a signal indicating the position ofthe character on the disc. The lamp 220 and photodiode 221 (seeright-hand lside of FIG. 17) cooperate with one another to producea'series of electrical pulses corresponding to each of the transparentslits 216 and 128 which are sent to a character counter 258. in each ofthe concentric rows of characters 41, 43 and 44, the uppercase lettersare located in a particular segment of the disc. For example, theuppercase letters are all in one half of the disc and the lowercaseletters in the other half of the disc.

There are 112 characters around the disc so that there are 56 uppercasecharacters and 56 lowercase characters. Each character pulse incrementsthe character counter 258. When the count in the character counterexceeds 56 the uppercase lowercase flop 255 is set indicating thatcharacters on that half of the disc are uppercase. When the count in thecharacter counter 258 exceeds 112 the counter itself is reset to zero bythe reset pulse on line 268 and the uppercase lowercase flop 255 is alsoreset indicating that characters on that half of the disc are lowercase.The zone equality comparator compares the state of the UCLC flop withthat of the uppercase lowercase flop in the typeface flops 248. Whencoincidence is detected by the zone equality comparator an enablingpulse is transmitted to the position equality comparator 256 indicatingthat the proper zone of the disc 48'is moving past the aperture of theshutter 63.

The equality comparator 256 continually compares the contents of theposition register 236 and the character counter 258. When equality isdetected a signal is sent to a flash control unit 260 which sends asignal to the flashlamp 52 and causes it to expose the proper characterwhich is projected onto the film. f

. The narrow slit 218 on the disc; 48 signals the start of a newrevolution of the disc 48. The way in which this is done is as follows:The train of pulses 266 (see bottom of FIG. 17) which is generated bythe photodiode 22l 'is sent to 'a'delay multivibrator 262 and also toone input lead of an AND" circuit 264. The trailing edge of each pulsegenerated by each slit 216 starts the multivibrator 262. Themultivibrator automatically turns off 200 microseconds later. Since thespacing between signals from adjacent slits 216 normally is considerablygreater than 200 microseconds, by the time the next signal appears atthe input of the AND" circuit 264, normally there is no signal on theoutput of the multivibrator circuit 262,.and there is no signal sent outover the line 268 to reset the counter. Thus, character pulses continueto be counted by the character counter 258. Then, when a signal isgenerated by the passage of the slit 218 between the lamp 220 and thephotocell 221, it creates a pulse which occurs at the same time that themultivibrator 262 produces an output signal. The AND circuit 264 thengenerates a reset pulse along line 268 to reset the character counter tozero and to start a new counting cycle.

As soon as the flashlamp 52 flashes, the escape step starts. The sameeight steps as are used in the read" cycle again are used in the escapestep, except that the character widths are added to instead of beingsubtracted from the accumulator 232 by the adder-subtractor 242. Thecharacter widths are transferred from the accumulator 232 to a motorregister 270 by means of a complementary transfer, with the result thatthe motor register 270 receives a signal corresponding to the width ofthe character next to be projected. The motor register 270 actually is abinary counter which operates a gate (not shown) which allows pulses 272to be transmitted to a carriage control unit 276 which transmits thepulses to the stepping motor to step it forward in a number of stepsequal to the compliment of counter 270. Thus, the number of pulses 272transmitted is equal to the relative width of the character next to beprojected. The flash command signal opens the gate and the motorregister 270 closes it. When the binary counter or motor register 270has counted a number of pulses 272 equal to the character width of thecharacter next to be projected, it shuts off the gate and the carriagestops. A signal is sent out over a line 274 when the count in thecounter is only two steps from being full in order to supply appropriatedeceleration signals to the stepping motor 140 to slow it down and stopthe carriage 74 precisely at the location desired. I

When the "escape" step is completed, the next character is read fromline storage memory. This sequence then is repeated for all of thecharacters and spaces in the line until the end-of-line signal isreceived, which signal starts the tape reader 34 in the reading of thenext line of characters.

A tab control circuit 280 is provided for the rapid printing of columnsof material. Also provided is a second accumulator 282 which stores theline deficit at the end of each column being printed. It should beunderstood that in the photocomposition of tabular materials; i.e.,materials arranged in columns, the line length input device 230 is setso that each column is treated as if it were a whole line of characters.Therefore, the remainder at the end of the material printed in thecolumns is a measure of the distance to the beginning of the nextcolumn, and the tab control circuit contains conventional circuitrywhich causes the accumulator 282 to transfer the line deficit to themotor register 270 to cause the carriage 74 to be stepped to thebeginning of the next column.

If the information in the columns is to be centered within each column,the line deficit is divided between the accumulators 232 and 282, andhalf of the line remainder is inserted at the beginningof the column bythe accumulator 232, and the other half of the remainder is insertedafter the printing of the characters in the column by means of theaccumulator 282 sending the other half of the remainder to the motorregister 270 and creating corresponding movement of the carriage 74.

A point-size encoder 278 is provided to compensate for displacements ofcharacters caused by changes in'the point size of the character images.The encoder 278 preferably comprises the brush and code platearrangement illustrated in FIGS. 3 and- 14 which produces a coded signalindicative of the relative position of the lens 54 relative tothe-character disc 48. The coded signal from encoder 278 is sent to thefunction decoder 244 which decodes the signal sent to it and sends asignal to the address register 228 which locates the appropriate addressin the memory 224 in which information is stored giving the number ofunits the carriage 74 must be moved to compensate for character imagedisplacements caused by point-size changes. That information is sent tothe width register 240, thence to the adder-subtractor 242, and then theaccumulator 232 which sends a signal to the motor register 270 whichcauses the carriage stepping motor 140 to step an appropriate number ofsteps to compensate for the horizontal displacement of the characterimages.

In order to enable the point-size change to be made manually, a stop"signal is recorded on the punched tape 32 and is read by the tape reader34. When the signal is read at the end of a line, the compositionequipment is stopped until the point size has been changed and anappropriate start switch has been pushed by the operator. Of course, ifthe point size is to be changed automatically by means of appropriatetape signal, such a stop" signal is not necessary.

ALTERNATIVE EMBODIMENTS P16. 8 shows an alternative embodiment 300 ofthe character or matrix disc of the present invention. There are twoconcentric rows of characters 302 and 304 on the disc 300. Each row cancontain characters of a given typeface or size, for example, Romancharacters can be located in row 302 and Italic characters in row 304.The exact timing of the flashlamp is determined by control slits 306 inthe opaque coating on the disc operating in cbnjunc'tion with aphotoelectric system as described in US, Pat. No. 2,790,362. Thesecontrol slits can be located on a circular band 308. Other circularbands shown at 310 can contain information representing the width ofeach character of the disc, if such information is desired. Aninitiating pulse signaling the beginning of a new disc revolution can begenerated, for example, by an additional slit 312 located between a pairof the slits 306.

In a machine of this kind it is desirable to provide means to easilyinterchange matrix discs. A disc interchanged system similar to the oneusedin machines sold under the trademark PHOTON can be utilized.

FIGS. 1 through 12 show an alternative embodiment of the charactertranslating apparatus of the present invention. In this embodiment,there is a slidable carriage 314 made of a light material suchas-aluminum. The carriage has extensions or flanges 316 and 318 whichcan contain bearings sleeves (not shown) by means of which the carriageis mounted so as to slide freely along rails 320 and 322 which aresecured to the general frame 324 of the machine (FIG. Carriage 314 isfurther provided with a rack 236 engaged by a pinion 328 located at theoutput of a cariable spacing and return mechanism comprising, in thepresent embodiment, a torque motor 330 (FIG. 9) and avariable'escapement or stepping motor 332. The continuously rotatingdisc 300 is secured to the frame of the carriage 314 by the flange 334of the motor housing of a disc drive motor 336. As it is now possible toobtain very lightweight motors, it has been found preferable in theembodiment under discussion to attach the motor 336 directly to thecarriage 314, although, as is evident from the description of thepreferred embodiment, other'means can be utilized to rotate the discfrom a motor at a fixed location on the base of the machine. Flexiblewires (not shown) connect the motor 336, flashlamp 338 and electricalcontrols of the carriage 314 to fixed terminals (not shown) on the baseof the machine.

The elements of the photoelectric control system of the machine are notshown since they are wellknown in the art. See the above-mentioned U.S.Pat. No. 2,790,362. In the present embodiment, the photoelectriccomponents preferably are located 180 away from the projection positionof characters for mechanical convenience. Openings 340 and 432 (FIG. 10)are provided in the carriage to allow passage of the light to energizethese electric controls and to project characters. The flash unit isshown at 338 (FIG. 10) attached to an arm 344 which is pivoted at 346 onthe carriage 314 in order to make it easier to interchange discs in avery short time by pulling arm 34 clockwise against a spring, not shown,to clear the disc area for easy removal.

The variable escapement device 332 can be similar to the escapementdevice described in U.S. Pat. No. 2,678,7l3, but it has been foundpreferable, in this embodiment, to use a variable escapement comprisingdifferentials similar to the ones shown in U.S. Pat. No. 2,933,990 butwith a reduced number of stages. In the machine being described, thebasic width unit has been selected to be one thirty-six of a six-pointEm. With six-point matrix characters on the disc 300, one basic unitspace is equal to six times one thirty-sixth of a point, or exactlyone-sixth of a point, or approximately 0.06 millimeters. If a variableescapement is used it can comprise five stages connected throughdifferential gearing. The construction of these stages can be' such asto cause a carriage displacement of three, six, eight, 10 and 12 basicunits when stage one, two, three, four and five are respectivelyenergized. The mechanical arrangement of the variable escapement can beexactly as described in U.S. Pat. No. 2,933,990, except that only fivestages are utilized. The stages 1, 2, 3, 4 and 5 are connected by theproper gearing to give speed ratios of one-half from stage 1 to stage 2;three-fourths from stage 2 to stage 3, four-fifths from stage 3 to stage4 and five-sixths from stage 6 to stage 5.

M Each escapement stage can comprise a solenoid-operated ratchetmechanism as described in U.S. Pat. No. 2,806,574. Also, a similarswitching arrangement can be provided with each stage to return thecarriage to an exact starting position after each line of characters hasbeen projected. To this effect it is preferably to provide for a one-wayclutch between the fourth and fifth stages so that the fifth stage onlywill be able to run backward, during the return of the carriage, asexplained in said patent.

The end of the return can be detected by the operation of limit switch348 of FIG. 10. The carriage return is initiated either by a manuallyoperated key in a keyboard-operated machine, or a carriage return signalin a tape-operated machine, as is well known, the return of the carriageis obtained by the action of motor 330. This motor can be of the torquemotor" class. It is also possible to return the carriage by a clutchmechanism such as those which are used in electric typewriters. Thus,with a simple four-stage variable escapement it is possible toaccurately space character images of any size without shifting gears orrelying on additional image displacing means such as prisms or mirrors.

Instead of a variable escapement mechanism, device 332 can be a steppingmotor. In this case no return mechanism is necessary as the steppingmotor can easily be reversed or return the carriage to its startingposition.

The optical components of this embodiment of the invention are thoseillustrated in FIGS. 6 and 7 and those described above in connectionwith FIGS. 6 and 7. It is preferred to use a zoom lens 350 (FIG. 9) asthe lens system of this embodiment. As has been indicated above, thezoom lens provides a continuously variable magnification ratio whilealso maintaining the images of characters in focus on the film (notshown in FIG. 9).

With machines provided with a multiple-style matrix disc the translatingmechanism described in U.S. Pat. No. 2,787,199 can be utilized. Anotheralternative is to change the relative positions of the disc and theprojection system by use of the variable spacing mechanism as will bedescribed with reference to FIGS. 11 and 12. V

.The carriage 314 is shown in partial cross section in FIG. 11. Theflashlamp is shown at 338, opposite the clearance aperture 342 of thecarriage. The illumination produced by the flashlamp is limited to onecharacter area by a window or aperture 352 in light shield 3S4 slideablyattached to the carriage 314 by buttons engaging slots 356 and 358. Thewindow can be moved from the position shown in solid lines in FIG. 12 toa position 360 by energization of a solenoid 362 (FIG. 11) attached tothe carriage which works against a return spring (not shown). Thedistance by which the window can slide on carriage 314 is equal to thedistance between two consecutive matrix character circles such as 302and 304 in FIG. 8. Thus, by selective energization of window solenoid362 it is possible to illuminate characters in a predetermined circle toobtain character images having one of several styles carried by thematrix disc 300.

At the same time as the window is displaced for style shift purpose, itis necessary to move the carriage in the forward or return direction bythe same amount as character rows are spaced, but in the oppositedirection so as not to affect the location of projected images. Thiscarriage movement is obtained, in the case in which a variableescapement is used, by the addition of a backspace mechanism actingeither directly on the carriage or, preferably, on the variableescapement. In the example in which the variable escapement stage of thehighest order causes the carriage to move 12 basic units for each step,the back space mechanism activates this stage backward by one toothincrement, or 12 units. The distance between consecutive charactercircles on the disc should measure an integral number of these steps,for example, five steps, or 60 units corresponding to 3.60 millimeters.

Assuming now that circle 302 containing Roman characters is being used,the window 352 will be in the position shown in solid lines in FIG. 12.If at one point in the line it is desired to shift to ltalic characterslocated 'on circle 304, the window solenoid 362 is energized to move theaperture 3.60 millimeters from its initial position to the position 360.At the same time, assuming that the normal direction of travel of thecarriage during the composition of a line is from'left to right as seenin FIG. 11, the carriage will be moved forward (to the right) 3.60millimeters by operating the highest stage of the variable escapementdevice four times, The result of this sequence is to move theilluminated area of the disc fonn circle 302 to circle 304 and placecircle 304 in the position previously occupied by circle 302 in relationto the optical system. When it is desired to return to Roman charactersthe procedure is reversed: the window solenoid 362 is deenergized andthe backspacing mechanism is operated four times to move the carriageback by 3.60 millimeters.

it is evident that the same system can be used with discs containingmore than two circles of characters.

Although the flashlamp 338 has been shown as attached to the carriage314, such a lamp is not necessary to illuminate the characters. A fixedlight source can be used with a' condensing system and light baffles, ora bundle of optical fibers can be sued as described in US. Pat. No.3,291,015.

The film is moved up for line spacing by a leading mechanism which isnot shown in FIGS. 6 to 12. This mechanism can be of the same type ofconstruction as the variable escapement.

The above description is intended to be illustrative and not inlimitation of the invention. Various changes or modifications in theembodiment set forth may occur to those skilled in the art, and may bemade without departing from the spirit or scope of the invention as setforth herein. For example, although it is preferred that thephotocomposition machine of the present invention be adapted to usepunched tape, it can be adapted to use magnetic tape as the informationinput medium, or it can be directly coupled to the composing keyboard asan integral unit, all as is well known in the art.

l. in photocomposition apparatus, character presentation means forsequentially presenting characters at a projection position, projectionmeans for selectively projecting said characters onto a characterimage-receiving surface, said projection means including optical meansfor focusing said characters on said character-receiving surface andmeans for changing the point size of said characters, means for holdingsaid optical means againstmovement during composition of a line relativeto said characterreceiving surface, and means for moving said characterpresentation means in steps along a path parallel to the base line ofsaid line of composition to provide spacing between characters in a lineof composition, the lengths of said steps being proportional to therelative widths of said characters, said point-size changing means beingpositioned in the optical path between said character spacing means andsaid character-receiving surface.

2. Photocomposition apparatus as in claim 1 in which said characterpresentation means comprises a character carrier member rotatable topresent'characters at said projection position in a continuous sequence,and including aperture means defining said projection position andmounted to move with said character presentation means.

3. Photocomposition apparatus as in claim 1 in which said projectionmeans includes a flashlamp mounted to move wit said characterpresentation means.

4. Photocomposition apparatus as in claim -I in which said projectionmeans, includes a projection lens, a pair of reflectors positionedtosuccessively reflect images received form said lens and onto saidimage-receiving surface, and means for mounting said lens and saidreflector pair so as to be movable toward or away from said characterprojection position.

5. Photocompositon apparatus as in claim in which said magnification andfocal length adjustment means includes a pair of arms for sliding saidlens and said reflector pair on a slide member, and releasable detentmeans for holding said lens and reflector pair in position.

6. Photocomposition apparatus as in claim 4 including means forsupporting said image-receiving surface in a substantially horizontalposition, and a third reflector intercepting the images from saidreflector pair and reflecting said images onto said iamge-receivingsurface.

7. Photocomposition apparatus as in claim 1 including means to shiftsaid character presentation means in a direction and in an amount suchas to relocate the vertical edge of a character at the margin of thecomposition on the imagereceiving surface after a change in charactersize has been made by means of said size changing means.

8. Photocomposition apparatus as in claim 7 including sensing meansresponsive to the movement of said adjustment means for providing saidshift.

9. In a photocomposition apparatus, character presentation means forsequentially presenting characters at a projection position, aperturemeans for defining said projection position, projection means forselectively projecting said characters onto a character-receivingsurface, said projection means including optical means for focusing saidcharacters on said character-receiving surface and meansfor changing thepoint size of said characters, and means for moving said characterpresentation means and said means together with one another along a pathparallel to the base line of said line of composition to provide spacingbetween characters in a line, said point-size changing means beingpositioned in the optical path between said character spacing means andsaid characterreceiving surface.

10. Photocomposition apparatus as in claim 9 in which said characterpresentation means is a movable support with spaced elongated arrays ofcharacters on it, said support being movably mounted on a movablecarriage driven by said moving means, said aperture means beingshiftable in the direction of motion of said carriage to locate saidprojection position along a selected one of said arrays.

11. Photocomposition apparatus as in claim 10 including a flashlampmounted to flash light through said disc only at said aperture, thelight beam emitted by said flashlamp covering an area including all ofsaid arrays.

12. Photocomposition apparatus as in claim 10 in which each of saidarrays represents a different character style, and

including means for shifting said aperture means in the direction ofmotion of said carriage for style shifting, and means for shifting saidcarriage by anamount equal to the shifting distance of said aperturemeans in a direction such that said projection position is returnedtothe relative position it had prior to the style shift. 7

13. In photocomposition apparatus, character presentation means foresequentially presenting characters at a projection position, projectionmeans for selectively projecting said characters onto acharacter-receiving surface, said projection means including opticalmeans for focusing said characters on said character-receiving surfaceand means for changing the point size of said characters, and means formoving said character presentation means in a first directioncorresponding to the direction of composition of a line of characters onsaid character-receiving surface in order to space characters therein,said character presentation means being positioned relative t'o'saidprojection position so that said characters move past said projectionposition in a second direction transverse to said first direction, saidpoint-size changing means being positioned in the optical path betweensaid character spacing means and said character-receiving surface.

14. Photocomposition apparatus as in claim 13 in which said seconddirection is substantially normal to said first direction. I

15. Photocomposition apparatus as in claim 13 in which said characterpresentation means comprises a rotatable support with concentric arcuatearrays of characters thereon, and means shiftable in said firstdirection to locate said projection position along one of said arrays.

16. In photocomposing apparatus, character support means for supportinga plurality of characters to be projected, means for'moving saidcharacter support means so as to move said characters past a projectionposition, projection means for projecting said characters onto acharacter-receiving surface, means for moving said support means in thedirection of a line of characters in increments the lengths of whichcorrespond to the relative widths of the characters to be projected, inorder to space character images on said character-receiving surface,said projection means including point-size magnification means having asingle lens structure permanently positioned to receive and magnify eachcharacter to be projected, and means for adjusting the magnification ofsaid lens structure to adjust the point size of the characters projectedonto said character-receiving surface, said point-size magnificationmeans being positioned in the optical path between said characterspacing means and said character-receiving surface.

17. In photocomposition apparatus, character presentation means forsequentially presenting characters at a projection position, projectionmeans for selectively projection means including optical means forfocusing said characters on said character-receiving surface and meansfor changing the point size of said characters, selective illuminationmeans for illuminating characters on said character presentation meansto send images thereof to said optical means, means for rotating saidcharacter presentation means relative to said illumination means, andmeans for moving said character presentation means together with saidillumination means so as to cause character images to be projected ontosaid character-receiving surface in a spaced-apart array with suitablespacing between characters, said point-size changing means beingpositioned in the optical path between said character spacing means andsaid character-receiving surface.

18. Photocomposition apparatus as in claim 17 in which said characterpresentation means has a plurality of arrays of characters, saidillumination means producing light beams each of which would passthrough at least one character in eacharray simultaneously but for thepresence of a shutter, and a shutter positioned between saidillumination means and said character presentation means to limit thepassage of said light beam through characters in only one of saidarrays.

19. In photocomposition apparatus, a slideable carriage, an opaque discwith a plurality of concentric rows of transparent characters on saiddisc, said disc being rotatably mounted on said carriage, a shuttermember adjacent said disc and having an aperture, said shutter memberbeing mounted on said carriage to swing said aperture into alignmentwith any selected one of said rows of characters, an illumination devicemounted on said carriage with said shutter between its light outlet andsaid disc, means on said carriage for swinging said shutter to alignsaid aperture with one of said rows, a stepping motor for driving saidcarriage in a direction parallel to the direction of a line ofcharacters being composed, the movement of said carriage being in stepshaving lengths equal to the relative width of characters to beprojected, a lens for magnifying images projected from said disc, first,second and third mirrors in the optical path between said lens and saidfilm, the first two mirrors reversing the initial direction of travel oflight from said lens, the third mirror changing said direction of travelby reflecting the light onto said film, said film being aligned in aapproximately horizontal plane at.the point at which the characterimages impinge, means for slideably mounting said lens and said firstand second mirrors so as to be movable independently towards and awayfrom said disc.

20. A transcription unit for a photographic-type composing machine,comprising a support for a light-sensitive sheet on which a line of textis to be composed; a matrix bearing a ring of master characters andcontinuously rotatable; a projection zone through which the mastercharacters travel during rotation of the matrix; a light source forilluminating a selected master character while traveling through theprojection zone; an optical system for projecting an image of anilluminated master character to a character-image position in a line oftext under composition, said optical system including means for changingthe point size of said character images as they are pro ected from saidmatrix to said light-senstrtlve sheet, and a matrix displacementmechanism operated during composition of the line to move the focal areaof the projection zone, by optical leverage, lengthwise of the line oftext under composition in order to space character images along saidline on said light-sensitive sheet, said point-size changing means beingpositioned in the optical path between said character-image spacingmeans and said light-sensitive sheet.

21. A transcription unit as in claim 20 including a displaceablecarriage on which said matrix is mounted and a matrix drive motormounted on said displaceable carriage effective to rotatably drive saidmatrix.

22. A transcription unit as in claim 20 including a plurality ofcoaxially arranged rings of master characters on said matrix and a ringselector associated with the projection zone operable to select themaster character ring from which the next character image is to beprojected.

23. A transcription unit as claimed in claim 22 in which the ringselector includes a mask spanning the projection zone, a Window in saidmask, and means to move said mask radially of the rings to bring saidwindow into registration with the positions in the projection zone ofdifferent master character rings.

24. A transcription unit for a photographic composing machine, includinga revolving matrix character carrier, projection means for projectingthe images of selected matrix master characters to an image plane, aphotosensitive surface located in the image plane, said projection meansincluding means for changing the point size of said character images,and means for producing relative movement between the matrix charactercarrier and the image plane whereby characters are spaced from eachother to form a line of composition on the photosensitive surface, saidmeans being arranged to move the revolving matrix the relative width ofeach projected character along a path parallel to the base line of saidline of composition, said point-size changing means being positioned inthe optical path between said character-spacing means and saidphotosensitive surface,

25. A transcription unit as in claim 24 wherein the revolving matrixcarrier is a disc having lihgt-transmitting master characters arrangedin concentric arcs and each depicted on an opaque background.

26. A transcription unit as in claim 24 including means for varying themagnification ratio of said projection lens, a film feed mechanismeffective to move said photosensitive surface in a direction normal to aline of composition, said film feed mechanism being ordinarily actuatedfollowing the composition of each line to provide line spacing and alsobeing adapted to be actuated during composition of a line whenever themagnification ratio of the projection lens is changed to move thephotosensitive surface a distance sufficient such that all thecharacters in a line of composition are projected to align on the samebase line.

1. In photocomposition apparatus, character presentation means forsequentially presenting characters at a projection position, projectionmeans for selectively projecting said characters onto a characterimage-receiving surface, said projection means including optical meansfor focusing said characters on said character-receiving surface andmeans for changing the point size of said characters, means for holdingsaid optical means against movement during composition of a linerelative to said characterreceiving surface, and means for moving saidcharacter presentation means in steps along a path parallel to the baseline of said line of composition to provide spacing between charactersin a line of composition, the lengths of said steps being proportionalto the relative widths of said characters, said point-size changingmeans being positioned in the optical path between said characterspacing means and said characterreceiving surface.
 2. Photocompositionapparatus as in claim 1 in which said character presentation meanscomprises a character carrier member rotatable to present characters atsaid projection position in a continuous sequence, and includingaperture means defining said projection position and mounted to movewith said character presentation means.
 3. Photocomposition apparatus asin claim 1 in which said projection means includes a flashlamp mountedto move with said character presentation means.
 4. Photocompositionapparatus as in claim 1 in which said projection means, includes aprojection lens, a pair of reflectors positioned to successively reflectimages received form said lens and onto said image-receiving surface,and means for mounting said lens and said reflector pair so as to bemovable toward or away from said character projection position. 5.Photocompositon apparatus as in claim in which said magnification andfocal length adjustment means includes a pair of arms for sliding saidlens and said reflector pair on a slide member, and releasable detentmeans for holding said lens and reflector pair in position. 6.Photocomposition apparatus as in claim 4 including means for supportingsaid image-receiving surface in a substantially horizontal position, anda third reflector intercepting the images from said reflector pair andreflecting said images onto said iamge-receiving surface. 7.Photocomposition apparatus as in claim 1 including means to shift saidcharacter presentation means in a direction and in an amount such as torelocate the vertical edge of a character at the margin of thecomposition on the image-receiving surface after a change in charactersize has been made by means of said size changing means. 8.Photocomposition apparatus as in claim 7 including sensing meansresponsive to the movement of said adjustment means for providing saidshift.
 9. In a photocomposition apparatus, character presentation meansfor sequentially presenting characters at a projection position,aperture means for defining said projection position, projection meansfor selectively projecting said characters onto a character-receivingsurface, said projection means including optical means for focusing saidcharacters on said character-receiving surface and means for changingthe point size of said characters, and means for moving said characterpresentation means and said means together with one another along a pathparallel to the base line of said line of composition to provide spacingbetween characters in a line, said point-size changing means beingpositioned in the optical path between said character spacing means andsaid character-receiving surface.
 10. Photocomposition apparatus as inclaim 9 in which said character presentation means is a movable supportwith spaced elongated arrays of characters on it, said support beingmovably mounted on a movable carriage driven by said moving means, saidaperture means being shiftable in the direction of motion of saidcarriage to locate said projection position along a selected one of saidarrays.
 11. Photocomposition apparatus as in claim 10 including aflashlamp mounted to flash light through said disc only at saidaperture, the light beam emitted by said flashlamp covering an areaincluding all of said arrays.
 12. Photocomposition apparatus as in claim10 in which each of said arrays represents a different character style,and including means for shifting said aperture means in the direction ofmotion of said carriage for style shifting, and means for shifting saidcarriage by an amount equal to the shifting distance of said aperturemeans in a direction such that said projection position is returned tothe relative position it had prior to the style shift.
 13. Inphotocomposition apparatus, character presentation means foresequentially presenting characters at a projection position, projectionmeans for selectively projecting said characters onto acharacter-receiving surface, said projection means including opticalmeans for focusing said characters on said character-receiving surfaceand means for changing the point size of said characters, and means formoving said character presentation means in a first directioncorresponding to the direction of composition of a line of characters onsaid character-receiving surface in order to space characters therein,said character presenTation means being positioned relative to saidprojection position so that said characters move past said projectionposition in a second direction transverse to said first direction, saidpoint-size changing means being positioned in the optical path betweensaid character spacing means and said character-receiving surface. 14.Photocomposition apparatus as in claim 13 in which said second directionis substantially normal to said first direction.
 15. Photocompositionapparatus as in claim 13 in which said character presentation meanscomprises a rotatable support with concentric arcuate arrays ofcharacters thereon, and means shiftable in said first direction tolocate said projection position along one of said arrays.
 16. Inphotocomposing apparatus, character support means for supporting aplurality of characters to be projected, means for moving said charactersupport means so as to move said characters past a projection position,projection means for projecting said characters onto acharacter-receiving surface, means for moving said support means in thedirection of a line of characters in increments the lengths of whichcorrespond to the relative widths of the characters to be projected, inorder to space character images on said character-receiving surface,said projection means including point-size magnification means having asingle lens structure permanently positioned to receive and magnify eachcharacter to be projected, and means for adjusting the magnification ofsaid lens structure to adjust the point size of the characters projectedonto said character-receiving surface, said point-size magnificationmeans being positioned in the optical path between said characterspacing means and said character-receiving surface.
 17. Inphotocomposition apparatus, character presentation means forsequentially presenting characters at a projection position, projectionmeans for selectively projection means including optical means forfocusing said characters on said character-receiving surface and meansfor changing the point size of said characters, selective illuminationmeans for illuminating characters on said character presentation meansto send images thereof to said optical means, means for rotating saidcharacter presentation means relative to said illumination means, andmeans for moving said character presentation means together with saidillumination means so as to cause character images to be projected ontosaid character-receiving surface in a spaced-apart array with suitablespacing between characters, said point-size changing means beingpositioned in the optical path between said character spacing means andsaid character-receiving surface.
 18. Photocomposition apparatus as inclaim 17 in which said character presentation means has a plurality ofarrays of characters, said illumination means producing light beams eachof which would pass through at least one character in each arraysimultaneously but for the presence of a shutter, and a shutterpositioned between said illumination means and said characterpresentation means to limit the passage of said light beam throughcharacters in only one of said arrays.
 19. In photocompositionapparatus, a slideable carriage, an opaque disc with a plurality ofconcentric rows of transparent characters on said disc, said disc beingrotatably mounted on said carriage, a shutter member adjacent said discand having an aperture, said shutter member being mounted on saidcarriage to swing said aperture into alignment with any selected one ofsaid rows of characters, an illumination device mounted on said carriagewith said shutter between its light outlet and said disc, means on saidcarriage for swinging said shutter to align said aperture with one ofsaid rows, a stepping motor for driving said carriage in a directionparallel to the direction of a line of characters being composed, themovement of said carriage being in steps having lengths equal to therelative width of characters to be projected, a Lens for magnifyingimages projected from said disc, first, second and third mirrors in theoptical path between said lens and said film, the first two mirrorsreversing the initial direction of travel of light from said lens, thethird mirror changing said direction of travel by reflecting the lightonto said film, said film being aligned in a approximately horizontalplane at the point at which the character images impinge, means forslideably mounting said lens and said first and second mirrors so as tobe movable independently towards and away from said disc.
 20. Atranscription unit for a photographic-type composing machine, comprisinga support for a light-sensitive sheet on which a line of text is to becomposed; a matrix bearing a ring of master characters and continuouslyrotatable; a projection zone through which the master characters travelduring rotation of the matrix; a light source for illuminating aselected master character while traveling through the projection zone;an optical system for projecting an image of an illuminated mastercharacter to a character-image position in a line of text undercomposition, said optical system including means for changing the pointsize of said character images as they are projected from said matrix tosaid light-senstitive sheet, and a matrix displacement mechanismoperated during composition of the line to move the focal area of theprojection zone, by optical leverage, lengthwise of the line of textunder composition in order to space character images along said line onsaid light-sensitive sheet, said point-size changing means beingpositioned in the optical path between said character-image spacingmeans and said light-sensitive sheet.
 21. A transcription unit as inclaim 20 including a displaceable carriage on which said matrix ismounted and a matrix drive motor mounted on said displaceable carriageeffective to rotatably drive said matrix.
 22. A transcription unit as inclaim 20 including a plurality of coaxially arranged rings of mastercharacters on said matrix and a ring selector associated with theprojection zone operable to select the master character ring from whichthe next character image is to be projected.
 23. A transcription unit asclaimed in claim 22 in which the ring selector includes a mask spanningthe projection zone, a window in said mask, and means to move said maskradially of the rings to bring said window into registration with thepositions in the projection zone of different master character rings.24. A transcription unit for a photographic composing machine, includinga revolving matrix character carrier, projection means for projectingthe images of selected matrix master characters to an image plane, aphotosensitive surface located in the image plane, said projection meansincluding means for changing the point size of said character images,and means for producing relative movement between the matrix charactercarrier and the image plane whereby characters are spaced from eachother to form a line of composition on the photosensitive surface, saidmeans being arranged to move the revolving matrix the relative width ofeach projected character along a path parallel to the base line of saidline of composition, said point-size changing means being positioned inthe optical path between said character-spacing means and saidphotosensitive surface.
 25. A transcription unit as in claim 24 whereinthe revolving matrix carrier is a disc having lihgt-transmitting mastercharacters arranged in concentric arcs and each depicted on an opaquebackground.
 26. A transcription unit as in claim 24 including means forvarying the magnification ratio of said projection lens, a film feedmechanism effective to move said photosensitive surface in a directionnormal to a line of composition, said film feed mechanism beingordinarily actuated following the composition of each line to provideline spacing and also being adapted to be actuated during composition ofa line whenever the magnificaTion ratio of the projection lens ischanged to move the photosensitive surface a distance sufficient suchthat all the characters in a line of composition are projected to alignon the same base line.